Effect of graded doses and a high dose of microbial phytase on the digestibility of various minerals in weaner pigs

An experiment with 224 weaner pigs (initial BW of 7.8 kg) was conducted to determine the effect of dose of dietary phytase supplementation on apparent fecal digestibility of minerals (P, Ca, Mg, Na, K, and Cu) and on performance. Four blocks, each with 8 pens of 7 pigs, were formed. Eight dietary treatments were applied to each block in the 43-d experiment: supplementation of 0 (basal diet), 100, 250, 500, 750, 1,500, or 15,000 phytase units (FTU) or of 1.5 g of digestible P (dP; monocalcium phosphate; positive control) per kilogram of feed. The basal diet, with corn, barley, soybean meal, and sunflower seed meal as the main components, contained 1.2 g of dP per kilogram of feed. Fresh fecal grab samples were collected in wk 4 and 5 of the experiment. Average daily feed intake, ADG, G:F, and digestibility of all of the minerals increased (P < 0.001) with increasing phytase dose. Digestibility of P increased from 34% in the basal diet to a maximum of 84% in the diet supplemented with 15,000 FTU, generating 1.76 g of dP per kilogram of feed. At this level, 85% of the phytate phosphorus was digested, compared with 15% in the basal diet. Compared with the basal diet, digestibility of the monovalent minerals increased maximally at 15,000 FTU, from 81 to 92% (Na) and from 76 to 86% (K). In conclusion, phytase supplementation up to a level of 15,000 FTU/kg of a dP-deficient diet improved performance of weaner pigs and digestibility of minerals, including monovalent minerals. Up to 85% of the phytate-P was digested. Thus, dietary phytase supplementation beyond present day standards (500 FTU/kg) could further improve mineral use and consequently reduce mineral output to the environment.     

Zinc bioavailability and tea consumption

One self-selected study (study A) and one laboratory-controlled study (study B) were conducted to investigate the effect of tea consumption on zinc bioavailability in healthy humans. The 14-day study A consisted of two 7-day experimental periods, while the 28-day study B consisted of two 14-day experimental periods. In study A eight subjects and in study B ten subjects were participated. Subjects of study A consumed self-selected diets and kept a record of foods eaten. In study B, subjects ate a constant and weighed laboratory controlled diet. In both studies, subjects consumed 8 g of instant tea during tea supplementation periods. Complete urine and fecal collections were made by subjects of both studies. Zinc contents of urine, fecal and food samples were determined by using Atomic Absorption Spectrophotometer. Mean zinc intakes of humans consuming self-selected diets were below the RDA. Mean urinary zinc excretion, fecal zinc excretion and zinc balance were unaffected by the tea consumption. Negative zinc balances in study A and positive zinc balances in study B were observed in both tea and no tea dietary treatments. Tea consumption showed a small but not statistically significant adverse affect on zinc bioavailability in humans.     

Effect of adjuvants on antibody responses of sheep immunised with recombinant pili from Dichelobacter nodosus

Objective To compare the effects of two oil emulsion adjuvants (incomplete Freunds adjuvant and a proprietary oil adjuvant), DEAE-dextran, L-tyrosine particles and Quil A on the humoral immune responses of sheep immunised with recombinant pili of Dichelobacter nodosus (strain A).
Procedure Antibody titres were studied for up to 32 weeks and were measured by bacterial agglutination and ELISA. The relative avidity of antibodies for pili was determined and the incidence and severity of adverse reactions at the site of injection of vaccines were recorded.
Results The oil emulsion adjuvants and Quil A were more effective than either DEAE-dextran or L-tyrosine at stimulating antibodies in sheep. The incidence and severity of adverse reactions was lower in sheep which received vaccines containing either Quil A or DEAE-dextran than in sheep which received vaccines containing oil emulsion adjuvants. L-tyrosine had no adverse effects.
Conclusion Quil A was as effective as oil adjuvants at stimulating high levels of antibodies against recombinant pili in sheep and had the significant advantage of being less irritant after subcutaneous injection.     

Nitrate and vitamin C from fruits and vegetables: Impact of intake variations on nitrate and nitrite excretions of humans

The objective of the study was to determine nitrate + nitrite excretions of human subjects fed variable amounts of nitrates and nitrites and vitamin C from fruits and vegetables. During four, randomly-arranged experimental periods of seven days each, the 12 apparently healthy, adult human subjects consumed laboratory controlled, constant, diets which were systematically varied in kinds of fruits and vegetable to provide the four following variations: 414 mg nitrate + nitrite and 23 mg vitamin C, 412 mg nitrate + nitrite and 177 mg vitamin C, 23 mg nitrate + nitrite and 39 mg vitamin C, and 21 mg nitrate + nitrite and 193 mg vitamin C per subject per day, respectively. Subjects made complete collections of urine and stools throughout the study. Regardless of type of experimental diet fed, no nitrates and nitrites were detected in the feces. Urinary excretion of nitrate + nitrite was significantly greater at the higher levels of nitrate + nitrite intake than at the lower intake levels. Increased intake of vitamin C at either level of nitrate + nitrite intake resulted in apparent decreased urinary excretions of nitrite + nitrate.Published as University of Nebraska Agricultural Research Journal Series no. 9936.     

Encephalitogenic activity of bovine basic proteins

Two basic proteins isolated from bovine white matter in connection with a study of the protein-bound phosphoinositides of central nervous system tisstue have been tested for encephalitogenic activity. The biological activity of these proteins, which is equivalent to that of basic encephalitogenic proteins isolated in other laboratories, suggested that they are identical.     

Are Pharmacological Interventions Between Conception and Birth Effective in Improving Reproductive Outcomes in North American Swine?

The objective of this review is to evaluate the effectiveness of using pharmacological compounds on reproductive outcomes, particularly litter size, in North American swine. While the opportunity to improve reproduction in North American pigs exists, numerous hurdles need to be overcome in order to achieve measureable results. In the swine industry, the majority of piglet losses are incurred during pregnancy and around farrowing. Over the last 20 years, a reduction in losses has been achieved through genetic selection and nutritional management; however, these topics are the focus of other reviews. This review will evaluate attempts to improve litter size by reducing losses at various stages of the reproductive process, from the time of conception to the time of farrowing, using pharmacological compounds. Generally, these compounds are used to either alter physiological processes related to fertilization, embryonic attachment or uterine capacity, etc., or to facilitate management aspects of the breeding females such as inducing parturition. Although some of the pharmacological agents reviewed here show some positive effects on improving reproductive parameters, the inconsistent results and associated risks usually outweigh the benefits gained. Thus, at the present time, the use of pharmacological agents to enhance reproduction in North American swine may only be recommended for herds with low fertility and presents an avenue of research that could be further explored.     

Clearance of para-aminohippuric acid in wethers consuming locoweed

AIM: To validate the use of para-aminohippuric acid (PAH) as a marker for measuring blood flow in wethers consuming a mixed diet of locoweed and blue grama hay.

METHODS: Fourteen sheep, stratified by bodyweight (BW), were assigned to one of three treatments: 0.8 mg swainsonine (SW)/kg BW (HI), 0.2 mg SW/kg BW (LO), and no SW (Control). Sheep were fed various ratios of locoweed and blue grama hay to deliver SW treatments, for 28 days prior to infusion of PAH. Concentrations of SW and activities of alkaline phosphatase (Alk-P) and aspartate aminotransferase (AST) in serum were measured to confirm exposure to SW and subclinical intoxication. A single 20-ml injection of 5% PAH was delivered into the jugular vein after subclinical intoxication had been achieved. Blood samples were collected and serum analysed for PAH immediately prior to injection, then every 5 min from 5–30 min, and every 10 min from 30–60 min, following injection of PAH.

RESULTS: Effective delivery of SW was evident from the greater concentrations of SW measured in the serum of HI compared with LO animals (p<0.05). No significant differences were detected in the rate of elimination (range 0.097–0.108 L/min), elimination half-life (range 6.62–7.24 min), apparent volume of distribution for the central compartment (range 7.14–9.72 L), and clearance (range 0.73–0.92 L/min) of PAH, between treatments.

CONCLUSIONS: Subclinical intoxication with SW did not affect the pharmacokinetics of PAH. Thus, use of downstream dilution of PAH is a valid method to determine the rate of blood flow in nutrient flux experiments that involve consumption of locoweed.     

Comparison of palm and mixtures of refined palm and soybean oils on serum lipids and fecal fat and fatty acid excretions of adult humans

The effects of palm (P) and mixtures of palmand soybean (PS), palmolein and soybean (POS),palmstearin and soybean (PSS) oils on serum lipids andfecal fat and fatty acid excretions of humans werestudied. Each oil was the dominant fat in dietsconsumed by ten normolipidemic live-in individuals.Test diets were assigned by randomization. All fourdiets had a similar influence on total cholesterol (TC),low density lipoprotein (LDL), high densitylipoprotein (HDL), very low density lipoprotein(VLDL), triglycerides (TG) and phospholipids (PL). Fecalfat excretion was higher (1.81, 1.80 g/d) with PS andPSS and lower (1.78, 1.42 g/d) with P and POS diets.Excretions of palmitic (C16: 0), oleic (C18: 1), andlinoleic (C18: 2) acids were similar for all diets.Excretions of stearic acid (C18: 0) were higher whenfeeding POS and PSS, and lower with feeding P and PS;the changes were statistically significant atp < 0.05. More linolenic acid (C18: 3) was excretedwhen P was fed compared to the feeding of PS, POS, andPSS. Changes in linolenic acid excretion between P andPOS were statistically significant at p < 0.05. It wasconcluded that there were no significant differencesin serum lipid concentrations due to feeding palm orany of the refined palm and soybean oil mixtures.However, a significant difference was found in C18: 0excretions with feeding POS and PSS compared to whenP and PS were fed. Similarly, significant C18: 3excretion was found with feeding P compared to whenPOS was fed.